The present invention relates to the field of electrical connectors and particularly to connectors for providing sequential connection and disconnection of circuits coupled thereto as the connector members are urged together or apart.
In contemporary electronic instruments, computers and the like, large numbers of solid state electronic devices are used, frequently in the form of integrated circuits. Each such integrated circuit device requires external electrical connection to a power source and usually requires further connections to couple signals to and from other circuit elements. Integrated circuits are usually mounted on printed circuit boards which have wiring thereon to inter-couple the integrated circuits on the same circuit board as well as to provide electrical connection from the integrated circuits to a connector assembly mounted thereon. This connector is sometimes known as a header and is utilized to couple the integrated circuits on the board with circuits on other boards as well as couple electrical power from an external bus to the circuits on the board.
Connectors utilized for this purpose usually have a plurality of female connectors, each identical to the other, which comprise the header. The header is designed to mate with a plurality of pins extending from a back panel. Each pin and female connector are usually quite small so that a large number of such female connectors are found in each header which occupies a small space.
While the above described connector arrangement has been used for some time, there are several disadvantages. The headers used, for example, comprise multipin connectors which must be carefully aligned with the pins on the back panel. Most headers which are economically feasable for use in computers, however, do not have alignment pins or the like therby making the headers difficult to plug into the mating connector on the back panel without possibly causing damage to the header or bending one or more pins on the back panel. In addition, headers are designed to be small in size to provide connection between many circuits in a very small space. Hence, the current carrying capacity of each such connection is low and several such connections must be coupled in parallel to connect power from the back panel to each printed circuit board.
The use of existing headers may also give rise to circuit failures when printed circuit boards are plugged and unplugged while power is on. Such possible failures are a risk associated with integrated circuits which are often sensitive to the sequence that power is turned on or off. While it is true that headers are designed to provide electrical connection to all circuits simultaneously as one is plugged into a back panel, in truth, such does not occur. Electrical power may be coupled to the circuits on the board before the ground is connected which may cause a circuit failure. Accordingly, existing headers may complicate maintenance of instruments or computers in which they are used as power must be turned off before a circuit board is replaced.
In view of the above described problems with existing headers, it is the principal objective of the present invention to provide a power connector for use with integrated circuits disposed on printed circuit boards which will prevent circuit failures from occurring due to improper power connection sequence.
It is a further objective of the invention to provide a connector having the above described attribute as well as having sufficient current carrying capacity so that excessive number of contact pins need not be used for providing needed power to a printed circuit board.
It is still another objective of the invention to provide a sequential power connector which can also be utilized to align a header mounted on the same printed circuit board as the board is plugged into the back panel.